This invention relates to dental hygiene. In particular, this invention relates to home-based methods for the removal of dental plaque.
Dental plaque is a thin almost colorless largely bacterial film that accumulates on teeth. The part of the tooth next to the sulcus, or circumferential space or trough between the gum tissue and the crown or root of the tooth, is extremely difficult to keep free of bacterial plaque. If plaque is permitted to accumulate, it will form tartar which is a rough hard material that adheres to teeth. Plaque and tartar build-up constitute the primary cause of periodontal disease. For these reasons it is desirable to have a safe and easy-to-use method of removing plaque at home, between visits to a dental professional.
Tooth brushing is the mainstay of dental therapy, but brushing cannot remove plaque from the tooth surfaces below the gum line or, to a lesser extent, between the teeth above the gum line. To disrupt plaque in this area manually, the patient must floss at least daily. However, compliance with prescribed flossing has been estimated at 3-18% in the United States.
xe2x80x9cSonicxe2x80x9d tooth brushes vibrate a bristled head at frequencies between 300 and 500 Hz and are purported to disrupt plaque on nearby inaccessible dental surfaces through vibration. Ultrasonically vibrated devices achieve a similar effect by vibrating at frequencies in excess of 20 kHz. Consumer products do not exist which deliver ultrasonic frequencies directly to oral surfaces and there may be some confusion with the impressive term xe2x80x9cultrasonicxe2x80x9d resulting from imprecision in the use of the similar sounding and accurate term xe2x80x9csonic.xe2x80x9d Consumer model xe2x80x9cultrasonic toothbrushesxe2x80x9d typical work by the downstream ultrasonic excitation of a stream of liquid which subsequently impinges on the teeth. It is believed that residual cavitational collapse in the acoustically relaxing fluid contribute to a cleaning action of the impinging stream, which stream may also contain dentifrices.
In contrast to consumer products, true ultrasonic tools have been commercially avaiably to dental professionals for aiding in the removal of tartar deposits, as an alternative to scraping performed by a dental hygienist. Such true ultrasonic tools may cause damage to teeth or gums by misapplication and are unsuitable for consumer use.
Regardless of the mode of action of xe2x80x9csonicxe2x80x9d or xe2x80x9cultrasonicxe2x80x9d consumer products aiding in the prevention and removal of plaque deposits, such tools, in common with their purely manually actuated counterparts, require proximation of an active tip or working surface to each dental surface to be cleaned. Therefore, while these acoustic or vibratory tools represent an advance in convenience and comfort over manual brushing and flossing in achieving a similar level of oral hygiene and improve compliance in patients who find flossing impalatable, there is further room for improvement in provision of safe, convenient and effective home dental therapies for the prevention and removal of plaque.
In a related technological area, it is known to clean small rigid objects, such as jewelry findings or watch parts, in an ultrasonic bath. While effective, such baths may not be able to accommodate part shapes which, however, do not exceed the volume of the basin or tray. For a given available cleaning volume, the bath devices are also relatively cumbersome to transport, being designed for table-top use in a fixed location. A more flexible sonic or ultrasonic cleaning method and associated device, able to handle a larger variety of parts for a fixed transportable weight and size, would therefore have utility for technicians working outside the lab, in the field.
It is an object of this invention to provide a method and/or device aiding in the prevention and removal of dental plaque.
It is a further object of this invention to provide such a method and/or device which is usable by a consumer.
In another aspect of the present invention, it is an object to provide a portable cleaning device and/or an associated method able to handle a wider variety of part shapes for a fixed transport weight and size as compared with present ultrasonic parts cleaners.
These and other objects will become apparent through an examination of the drawings and descriptions contained herein.
As discussed above, existing methods and devices aiding in the removal of dental plaque, whether purely manual or power assisted, require application in the mouth at or near each targeted dental surface in order to be effective. A more efficient, easily used device would be one which processed a broader swath of the mouth at one pass, ideally including the entirety of the inside of the mouth in one cleaning operation. Existing vibratory dental cleaning devices, whether operating in a sonic or an ultrasonic frequency range, remain topical in application. However, in other cleaning applications, it is known to create an ultrasonic bath, i.e., a container enclosing an ultrasonically excitable active volume of cleaning fluid into which a plurality of parts may be inserted for simultaneous cleaning. It is found in such applications, as used for the cleansing of jewelry fittings and other small parts, that the exact placement of the parts in a volume of cleaning fluid is not critical and that parts immersed in many locations in the fluid may be effectively cleaned at the same time. In the prior art, the container is manufactured of a rigid material such as steel and one or more ultrasonic transducers are permanently affixed to the container exemplarily by cement. Ultrasonic vibrations are transmitted from the transducer through the rigid container and into an active fluid volume.
The oral cavity or mouth constitutes a naturally occurring container for the retention of fluid. Furthermore, a physically competent patient may retain a significant volume of fluid in the mouth, substantially filling the space between jaw and palate without excessive swallowing or leakage past the lips. The present invention accordingly recognizes that the oral cavity constitutes a suitable natural enclosure for creating an ultrasonic bath for cleaning of the teeth. The oral cavity is largely lined with at least an integument of soft tissue, as opposed to a rigid surface, and is at least partially variable in overall shape and volume. The volume and shape of the oral cavity is easily modified by an individual by controlling the angle of the jaw and positions of soft tissue processes such as the lips, the tongue, the uvula, the epiglottis, and anterior and posterior structures known as the pillars of the fauces, between which structures passes an orifice known as the isthmus of the fauces, i.e, the throat. The throat and the lips can be closed by voluntary muscular action, rendering the oral cavity a substantially fluid-tight container.
In general, in a novel method of acoustic cleaning in accordance with the present invention, an at least semi-flexible cavity or sack may be filled with a working fluid or solvent and at least one article to be sonically cleaned. An elongate sonic or ultrasonic probe is introduced into the cavity by means of a flexible orifice or embouchure which is subsequently made fluid tight around a shaft of the probe. The probe is activated and an enclosed volume of fluid is acoustically energized, providing a cleaning action of the enclosed article or articles. It is believed, in the case of ultrasonic energization, that the associated cleaning action is attributable to ultrasonic cavitation in the working fluid at a rigid surface. It should be recalled in the context of the present invention that plain water is properly regarded as a solvent.
In a particular application of the present invention to oral hygiene, the semi-flexible cavity may be the human mouth, an elongate sonic probe being inserted past the lips, which form a substantially fluid-tight seal around a shaft of the sonic probe, an additional substantially fluid tight seal being formed by further muscular action at the throat. An energization of the probe is associated with a cleaning action on exposed dental surfaces, and in particular the removal of plaque deposits. The mouth is first filled with a non-toxic cleaning composition or wash, typically but not necessarily by drinking from a cup. Subsequent to the filling, a vibratory probe is inserted past the lips and energized. In a first embodiment of the instant procedure, the probe is held in a fixed location, for example near the center of the mouth, for a present time, much as one would obtain a reading from an oral thermometer. A timer on an ancillary external unit providing a source of vibratory energy to the probe alerts the user when a preset cleaning interval has expired. The deenergized probe is then removed from the mouth, and the cleaning solution expectorated. An optional rinse step may further remove loosened detritus for the mouth.
In a second embodiment of a hygienic procedure in accordance with the instant invention, the probe is actively moved about the mouth by the user during an interval of energization. Vibratory energy may thereby be applied more strongly to nearby teeth, or focussed by the internal geometry of the hard surfaces of the mouth, and thereby, by moving the probe and accommodating the movement by cooperative voluntary movement of the jaw and areas of soft tissue such as the cheeks and tongue, a more uniform cleaning of dental surfaces ultimately achieved. This embodiment represents an intermediate case between dedicated cleaning of each tooth surface by direct mechanical contact, as realized by brushing or flossing, and a single step whole mouth cleaning. It thus still represents a time-saving over detailed mechanical contact, while providing a comparable degree of cleaning.
In another aspect of the present invention, the probe has an operating frequency, and that frequency may be ultrasonic. In a particular embodiment, frequency and energy level may be under user control, either through one of two or more presets, or continuously over a preset range. Thus embodiments may range from a xe2x80x9cbasicxe2x80x9d model, with fixed power level and timing, designed to be inserted in a user""s mouth for a preset interval, to xe2x80x9cadvancedxe2x80x9d models, allowing a user to adjust power, frequency and duration, within established preset limits.